1. Field of the Invention
The present invention generally relates to marine vessels and components related thereto and more specifically to a dive and/or boarding ladder for a rigid inflatable boat.
2. Description of Related Art
Rigid-hulled inflatable boats, also known as rigid inflatable boats (RIB) are popular sea-faring vessels that are stable, seaworthy, and versatile. RIBs are useful in recreational, commercial, and military applications. A typical RIB comprises a solid, traditionally v-shaped hull having flexible inflatable tubes disposed around the gunwale (i.e. top edge of the side) thereof. RIBs are designed to be hydroplaning boats and can be powered by an outboard motor or an inboard water-jet motor. The hull of the RIB may be comprised of wood, steel, aluminum, fiberglass, glass-reinforced plastic, or combinations thereof. The inflatable gunwale tubing is often comprised of a resilient rubber or plastic composite such as, for example, hypalon, polyvinyl chloride or polyurethane. Many RIBs can outperform traditional fiberglass boats and often are more difficult to sink and provide improved ride and handling in heavy seas. Additionally, the relatively flexible and durable gunwale tubing provides protection for the RIB and other vessels and structures it may come in contact with.
As noted, RIBs are quite versatile and can be used as rescue craft, patrol vessels, dive boats, or tenders for larger boats. With respect to rescue and dive use, access between the vessel and the water is typically provided over the gunwale of the RIB because the tight geometry, narrow transom, and overall configuration of the vessel do not provide adequate space for a dive ladder or other boarding means. Although boarding/de-boarding over the gunwale is not difficult for an able-bodied individual, it is not ideal when dealing with an injured individual who may be strapped to a stretcher or other rescue device. Over-the-gunwale boarding/de-boarding is likewise not ideal for a rescuer/diver that may be carrying several pounds of cumbersome equipment.
Several attempts at providing a ladder or other boarding device for sea-faring vessels have been made. For example, U.S. Patent Application Publication No. 2011/0132252 to Kaye describes a removable casting deck assembly for a rigid inflatable boat includes a deployable swim ladder which is stored in a top deck panel, and is rotated through a hinge assembly to a position enabling use. The deck assembly includes curved stabilizers where are disposed around the curvature of the inflatable tubing along the gunwale of the vessel.
U.S. Pat. No. 7,861,663 to Sedlack provides a portable boarding ladder for inflatable watercraft, which is attached to a pontoon or side wall tube of the boat. The ladder is attached to a rubberized portion of an inflatable boat without the use of piercing fasteners and does not require a hard point mounting structure. A base ladder section and a climbing ladder section are pivotally coupled together and supported in an operative, stand-off boarding position along a curved hull surface of a pontoon boat by a pair of hook support brackets and a pair of latch retainer brackets. The support brackets are bonded to the pontoon by adhesive deposits. A lateral cross bar tubing segment of the base ladder section is supported by hanging engagement on the hook brackets. A pair of side rail tubing segments of the climbing ladder section are retained and secured against lateral shifting displacement and rotation relative to the pontoon by snap-fit engagement against resilient arm portions of the latch retainer brackets.
U.S. Pat. No. 5,541,507 ‘to Gibellato illustrates a universal folding ladder for inflatable boats, having an L-shaped upper section which is supported by the gunwale of the boat and one or more ladder sections pivotably attached to the bottom of the upper section and extending into the water to provide a stand-off boarding position. The upper section includes a plurality of slats or boards providing a standing deck surface at the top of the inflatable tubing/gunwale.
U.S. Pat. No. 4,186,820 to Cosman provides a boarding ladder for use on an inflatable boat. The system includes a strap assembly placed around the inflatable tubing which is adapted to mount a rigid ladder to the boat. The rigid ladder portion has a pair of struts extending from the ladder toward the board. The struts cooperate with a horizon cross-piece at the top of the ladder to mount the ladder in an orientation extending downward and outward from the side of the board, and prevent the ladder from rotating under the boat when in use.
U.S. Pat. No. 3,498,410 to Storch provides a vessel ladder hingeably mounted to the gunwale of a traditional vessel wherein the ladder includes a stand-off rod transversely disposed between the ladder and the side of the vessel to provide support and proper attitude of the ladder when in use.
Although the prior art provides some useful boarding ladder designs for inflatable vessels, none extend far enough into the water and most cause the gunwale tubing to deform or deflect outwardly. Additionally, none provide a sufficiently sturdy and useful platform for entry and exit. Indeed, the prior art relies on the inflatable tubing to provide vertical support at the top of the ladder, which causes a reduction in ladder stability and leads to unwanted deformation of the tubing during use. Consequently, there is a need in the art for a dive/boarding ladder useful for inflatable vessels that provides a useful upper platform, an extended-length ladder portion, and overall stable and sturdy design that resists rotation and/or twisting of the ladder and deformation of the vessels inflatable gunwale tubing.
It is, therefore, to the effective resolution of the aforementioned problems and shortcomings of the prior art that the present invention is directed. However, in view of the dive/boarding ladders in existence at the time of the present invention, it was not obvious to those persons of ordinary skill in the pertinent art as to how the identified needs could be fulfilled in an advantageous manner.